Roller Chain Pitch Chart

What it is

ANSI (ASME B29.1) roller chain is named by a number. The digits before the last one give the pitch in eighths of an inch. The last digit gives the type: 0 is standard roller chain, 1 is lightweight, and 5 is rollerless (bushing) chain. So #40 is 4/8 = 1/2 in pitch standard chain, and #60 is 6/8 = 3/4 in pitch.

How to read it

• Pitch is the distance from one pin center to the next.
• Measure across several pitches and divide, rather than measuring one link. This also shows wear.
• Suffixes add detail: -2 or -3 means double or triple strand; H means heavy series (thicker side plates); other letters are maker-specific.
• Count pins or pitches for the length. Chain is sold in feet and pitches.

Pitch chart

Key points

• British Standard (B-series) chain, such as 08B or 16B, has pitches close to ANSI sizes but different roller and width dimensions. It does not run on ANSI sprockets reliably.
• 41 and 40 share a pitch but not a width. Sprockets are not interchangeable.
• Replace chain and sprockets together when sprockets show hooked teeth.
• Working loads and wear limits come from the chain maker, not from the chain number.

Common mistakes

• Measuring one link and calling it the pitch.
• Mixing ANSI and British chain because the pitch is the same.
• Joining new chain to old, stretched chain.

Governing standards: ASME B29.1 (precision power transmission roller chains); ISO 606 (international A- and B-series); chain maker data.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.